Since Sir Robert Menzies stepped down as prime minister in January 1966, the Liberal Party of Australia has had 13 leaders. This leaves 11 — if Harold Holt (who died in office in December 1967) and Scott Morrison are excluded.

Of the 11, a quarter campaigned against the Liberal Party in their years after politics, while another has chosen to effectively run dead as the Liberals face perhaps their most important by-election since the party was founded in late 1944.

Last Saturday evening, television carried footage of former Liberal leader John Hewson campaigning in Wentworth, assisted by a group of green-left anti-mining activists. He called for the Liberal Party to get “a drubbing” in next Saturday’s by-election.

Hewson described the Liberal Party’s Dave Sharma as “a good candidate”. Yet he wants the electors of Wentworth to “register” a substantial protest vote against the government “or any other candidates that don’t understand the magnitude and urgency of the climate change challenge”.

He is urging electors to vote for Labor, the Greens and independents (such as Kerryn Phelps and Licia Heath) ahead of Sharma. He wants traditional Liberals to vote against Sharma on October 20 “before returning to vote Liberal at a general election in six months’ time”. This is disingenuous.

Hewson knows that once an independent wins a seat such as Wentworth, they are difficult to dislodge — since the likes of Phelps, if successful on October 20, would face the general election next year with all the benefits of incumbency. If Phelps prevails over Sharma, she is likely to be the member for Wentworth for some time.

In his regular Sydney Morning Herald column on Wednesday, Hewson put his activism into words. He urged traditional Liberal voters in Wentworth to lodge a protest vote, declaring that he saw himself “as an Australian first and a member of the Liberal Party second”. Yet Hewson did not sign off his column as “an Australian” but rather as “a former Liberal opposition leader”.

Fairfax Media and the conservative-free zone that is the ABC readily give space and time to former Liberal Party identities who delight in bagging the party that once delivered them parliamentary seats. The thoughts of Hewson can frequently be found in the Herald and on ABC TV programs such as The Drum.

Hewson stands in the tradition of John Gorton (who led the Liberals from 1968 to 1971) and Malcolm Fraser (who led the party from 1975 to 1983). It’s possible that Malcolm Turnbull will join this group. Certainly he has made life difficult for the Liberals by resigning as the member for Wentworth and causing an unnecessary by-election about six months before the likely date of next year’s federal election. Moreover, so far at least, he has not made an unequivocal statement in support of Morrison or Sharma.

In March 1971, Gorton lost support in the partyroom and was replaced as prime minister by William McMahon. Gorton blamed Fraser for undermining him; their enmity lasted until the former’s death in 2002. Gorton ran unsuccessfully as an independent for a Senate seat in the ACT in 1975. He was a constant public critic of the Fraser government.

In turn, Fraser became a leading public critic of John Howard and his government from not long after the Coalition’s election victory in March 1996 until its defeat in November 2007. Once a hated figure among the Left, in his final years Fraser was wont to receive standing ovations by leftists at taxpayer-funded literary festivals.

In 1992 (during the Keating government) Fraser co-­operated with anti-communist ­activist BA Santamaria and academics John Carroll and Robert Manne with a view to establishing a new political grouping that would advocate protectionism and economic intervention. Fraser was the designated leader. This was first revealed by Patrick Morgan and confirmed in Malcolm Fraser: The Political Memoirs, which Fraser co-wrote with Margaret ­Simons. The project got nowhere.

In 2015 (during the Abbott government), Crikey’s Sally Whyte revealed that in the months leading up to his death, Fraser was at it again. He attempted to set up a new party, Renew Australia, that would oppose both the major parties since they allegedly advocated “policies ever more corrosive of our national spirit of fairness and justice”. Fraser died in March 2015. He formally had resigned his Liberal Party membership in 2010.

Like Hewson, Fraser was much sought after to comment on the Liberal Party in his capacity as a former leader. This gave a sense of credibility to his criticisms that they otherwise would have lacked. At least Fraser in due course resigned his membership. At his green-left-supported rally this week, Hewson indicated he retains his Liberal membership.

With the occasional exception, a person who becomes a political leader in a democracy is talented to some extent. Yet the likes of Gorton, Fraser, Hewson and Turnbull would never have obtained the positions they did without the support of the Liberal Party. In other words, the party creates the leaders. In return, it is reasonable to expect that former leaders will respect the party that made their success possible.

Liberal leaders such as Billy Snedden, Andrew Peacock, John Howard, Alexander Downer and Brendan Nelson, after their retirement from politics, did not attack the party that made them. McMahon made some criticisms of the Fraser government but they were of little moment. Abbott was not a disrupter in the lead-up to the 2016 elections, where Turnbull led the party to a near defeat. He did criticise Turnbull during the past two years but now is clearly supporting Morrison.

It remains to be seen whether Turnbull will follow Howard’s tradition or that of Hewson. What is known is that Hewson is calling for a majority Coalition government to become a minority administration. If this occurs, Labor will be even closer to government. It’s not an outcome that Menzies ever favoured.